RE: [AV Media Matters] medialine CD-R permanence article

[Charles Repka <Charles.P.Repka@abc.com>]

I now have had a chance to read Jacob Trock's article and at best,
it can be said he just scratches the surface of this rather
complicated problem.  His conclusion that Pthalocyanine discs have a
problem recording at 1 X is based on results from 1 disc.  From a
single manufacturer.  You really need a lot more data.  Such as,
discs from different manufacturers, different productions runs from
the same manufacturer and different manufacturing production lines
from the same manufacturer.   You also need to have a "reference
recorder" to make all the recordings and a "reference player" for
making all the playback tests to eliminate some of the
recorder/player variables.  The hardest thing about making tests
like this is keeping the number of variables to a minimum.  Ideally,
you should be able to only change one variable at a time but that is
not always possible.

Charles Repka

>Why is this BLER increase then related especially to the
>pthalocyanine dye
>discs?
>If pressing or servo tracking problems is a factor you should
>expect an
>equal
>problem with all dyes and pressings.
>
>
>lars gaustad
>FilmSoundVideo-dep
>Media Lab
>National Library of Norway
>N-8607 Mo i Rana
>
>phone:+47 751 21 154
>fax:     +47 751 21 222
>mobile:+47 959 48 393
>e-mail: lars.gaustad@nb.no
>           larsg@monet.no